Mechanism of silver nucleation upon the radiation-induced reduction of its ions in polyphosphate-containing aqueous solutions

Long-lived (hours to days) silver clusters, Ag ₄ ²⁺ , Ag ₄ ⁺ , Ag ₈ ²⁺ , etc., are formed upon the radiation-induced reduction of Ag⁺ ions in aqueous solutions containing sodium polyphosphate. The efficiency of the cluster formation decreases and the stability of the clusters increase with a rise in the concentration of the polymeric stabilizer. In the course of the aggregation of clusters, their sizes increase, quasi-metallic particles emerge, and the process terminates with the formation of silver nanoparticles. The mechanism of silver nucleation upon the radiation-induced reduction of silver ions in aqueous solutions is discussed.